A manual transmission may be shifted when a driver depresses a clutch pedal and adjusts a position of a manual shift lever. During an upshift from a lower (e.g., first gear) to a higher (e.g., second gear) gear, a driver opens a clutch by depressing a clutch pedal. The driver also changes a position of a shift lever to release the gear being exited and enter the next higher gear. For a smooth shift, the driver waits until the engine speed has decreased to a speed that is near the transmission input shaft speed before closing the manually operated clutch. If the driver releases the clutch pedal and closes the clutch sooner than is desired, a driveline torque disturbance may be experienced by the driver. However, if the driver closes the clutch when engine speed is near transmission input shaft speed, the shift may be smooth and the driver may experience a smooth progression in driveline torque. Engine torque may be increased in response to a change in a requested or desired engine torque. Nevertheless, it may be difficult for a driver to judge when engine speed is near transmission input shaft speed because displays of transmission input shaft speed are uncommon. Consequently, drivers may experience driveline torque disturbances from time to time, especially during conditions where the driver is attempting to facilitate a quick shift.
The inventors herein have recognized the above-mentioned disadvantages and have developed a driveline operating method, comprising: receiving sensor input to a controller; judging a shift of a manual transmission is in progress via the controller in response to the sensor input; and increasing a load applied to an engine via the controller based on the judgement.
By decreasing engine speed via applying a load to the engine responsive to a transmission gear upshift, it may be possible to provide the technical result of reducing a time for manually shifting a manual transmission. In particular, engine speed may be reduced quickly to transmission input shaft speed by applying a load to the engine responsive to an indication of an upshift. Lowering engine speed to transmission input shaft speed sooner may allow a driver to release a clutch sooner without experiencing an undesirable driveline torque disturbance. Further, in some examples, the manual upshift may be anticipated so that actions may be taken to before the actual upshift is in progress to overcome lag time of some types of load actuators.
The present description may provide several advantages. In particular, the approach may reduce manual transmission gear upshift times. Further, the approach may reduce driveline torque disturbances. Further still, the approach may be provided even with some actuators that may not respond as fast as is desired.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.